major effort has been made to clone the gene encoding hamster emale protein (FP). This protein is a hormonally regulated omponent of the acute phase response. Messenger RNA from the iver of male and female hamsters has been prepared and ranslated in vitro. The translation has been shown to contain aterial precipitable with antiserum to FP and it has been hown that there is more of this material in translated mRNA rom females than from males. In addition, protein sequencing rom a site of CNBr cleavage toward the carboxyl terminus of FP as identified a region from which the nucleotide coding equence can be inferred with a low level of ambiguity. This hould make possible the preparation of a synthetic nucleotide robe specific for FP. In the course of work on FP, it has een of interest to investigate the class I major istocompatibility antigens of the hamster. Using a class I HC probe from the rabbit it has been shown that the hamster as a large number of genes with very high homology to class I enes of other species. This eliminates one possible xplanation for the low level of polymorphism observed in class genes in this species. uring the year, the specificity of a panel of antibodies efining rabbit lymphocyte cell surface antigens has been urther investigated. The possibility that some of these ntibodies recognize glycolipids is being examined. Rabbit ouse hybridomas (RMH) which have been prepared in this aboratory are under study using the technique of in situ ybridization in an attempt to determine the site of ntegration of the rabbit immunoglobulin genes in the mouse enome.